import * as React from 'react'
import ReactDOM from 'react-dom'

export const composeEventHandlers = <E>(
  originalEventHandler?: (event: E) => void,
  ourEventHandler?: (event: E) => void,
  { checkForDefaultPrevented = true } = {},
) => {
  return function handleEvent(event: E) {
    originalEventHandler?.(event)

    if (checkForDefaultPrevented === false || !(event as unknown as Event).defaultPrevented) {
      return ourEventHandler?.(event)
    }
  }
}

/**
 * Flush custom event dispatch
 *
 * React batches *all* event handlers since version 18, this introduces certain considerations when using custom event types.
 *
 * Internally, React prioritises events in the following order:
 *  - discrete
 *  - continuous
 *  - default
 *
 * https://github.com/facebook/react/blob/a8a4742f1c54493df00da648a3f9d26e3db9c8b5/packages/react-dom/src/events/ReactDOMEventListener.js#L294-L350
 *
 * `discrete` is an  important distinction as updates within these events are applied immediately.
 * React however, is not able to infer the priority of custom event types due to how they are detected internally.
 * Because of this, it's possible for updates from custom events to be unexpectedly batched when
 * dispatched by another `discrete` event.
 *
 * In order to ensure that updates from custom events are applied predictably, we need to manually flush the batch.
 * This utility should be used when dispatching a custom event from within another `discrete` event, this utility
 * is not nessesary when dispatching known event types, or if dispatching a custom type inside a non-discrete event.
 * For example:
 *
 * dispatching a known click 👎
 * target.dispatchEvent(new Event(‘click’))
 *
 * dispatching a custom type within a non-discrete event 👎
 * onScroll={(event) => event.target.dispatchEvent(new CustomEvent(‘customType’))}
 *
 * dispatching a custom type within a `discrete` event 👍
 * onPointerDown={(event) => dispatchDiscreteCustomEvent(event.target, new CustomEvent(‘customType’))}
 *
 * Note: though React classifies `focus`, `focusin` and `focusout` events as `discrete`, it's  not recommended to use
 * this utility with them. This is because it's possible for those handlers to be called implicitly during render
 * e.g. when focus is within a component as it is unmounted, or when managing focus on mount.
 */
export const dispatchDiscreteCustomEvent = <E extends CustomEvent>(
  target: E['target'],
  event: E,
) => {
  if (target) ReactDOM.flushSync(() => target.dispatchEvent(event))
}

export const useIsomorphicLayoutEffect =
  typeof window !== 'undefined' && typeof window.document !== 'undefined'
    ? React.useLayoutEffect
    : React.useEffect

export const clamp = (value: number, [min, max]: [number, number]): number => {
  return Math.min(max, Math.max(min, value))
}
